Apparatus having improved control means for producing nonwoven fabrics

ABSTRACT

Apparatus for producing nonwoven net fabrics composed of adhered warp and weft thread sheets, including means for winding a continuous weft thread around thread support means to form a plurality of thread sections which are advanced in generally spaced parallel relation to form the weft sheet, and means operatively associated with the winding means for sensing a predetermined condition and for advancing the thread sections in response thereto to facilitate uniform positioning of the thread sections in the weft sheet.

7 United States Patent Inventor Milton M. Bolles Spartanburg, SC.

Appl. No. 874.121

Filed Nov. 5, I969 Patented July 20, I971 Assignee Deering Milliken Research Corporation Spartanburg, SC.

APPARATUS HAVING IMPROVED CONTROL MEANS FOR PRODUCING NONWOVEN FABRICS 14 Claims, 6 Drawing Figs.

us. Cl 28/1, 242/4212, 156/440 Int. Cl D02g 3/00, D04h 3/02 Field of Search 242/4712,

47.13; 28/1 CL, 1; 156/176l79, 439, 440

[56] References Cited UNITED STATES PATENTS 1,358,094 11/1920 Morris 28/] (CL) 2,962,080 11/1960 Hirsch 156/440 3,340,584 9/1967 Kalwaites.. 28/1 (CL) 3,422,511 1/1969 Seguin 28/1 (CE) 3,430,312 3/1969 Drummond 28/1 Primary Examiner-Stanley N. Gilreath Attorneys-Norman C. Armitage and H. William Petry ABSTRACT: Apparatus for producing nonwoven net fabrics composed of adhered warp and weft thread sheets, including means for winding a continuous weft thread around thread support means to form a plurality of thread sections which are 4 advanced in generally spaced parallel relation to form the weft sheet, and means operatively associated with the winding means for sensing a predetermined condition and for advancing the thread sections in response thereto to facilitate uniform positioning of the thread sections in the weft sheet.

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MILTON M. BOLLES A OR NEY APPARATUS HAVING IMPROVED CONTROL MEANS FORPRODUCINGNONWOVEN-FABRICS This invention relates to the production of nonwoven textile net fabrics, and more particularly-to an improved apparatus having control meansfor facilitating uniform formation of the weft thread sheet employed. in the formation of such nonwoven netfabrics.

Apparatus for producingnonwoven textile net fabrics are well known. One type of such apparatus comprises means for continuously winding one or more.v continuous threads about a pair of spaced thread support members ina plurality of parallel loops, or thread sections, which are moved laterally along the support membersin generally parallel spaced relation'to form a weft thread sheet. One or more warp thread sheets are brought by suitable guide means. into contiguous coplanar relation with the moving weft sheet and are adhesively secured thereto to-form the composite nonwoven net fabric. These fabrics are widely used as reinforcement in various laminated products, such as synthetic polymeric sheets and films, paper sheets, andthe like, and as a support backing for carpets and multipart materials, such as ceramic orwooden floor tiles. Such net fabrics also are used. as packing materials, screening material for windows, doors and the like.

Apparatus-of the; general type described aredisclosed in French Pat. No. l,208,968 and French Addition Pat. No. 79,765 thereto, as well as-,U.S. Pat. No. 3,422,5ll and'my copending U.S. Pat. applications Ser. No. 798,044filed Feb. l0, 1969;and Ser. No. 796,l35'filedFeb. 3, 1969.

In the above mentioned French Addition-Pat. and U.S. Pat; No. 3,422,5'] l, the spaced yamsupport members consist of a pair of elongate helical'members, such as springs, which extend generally parallel to eachother in-side-by-side, spaced relation and are mountedfor rotation about their longitudinal axes. The means for winding acontinuous thread aboutthe support members to form the weftsheet comprises a rotating tubular thread guide arm, the outer-end of' which'describes a circularpath about the supportmembers such that, as'the continuous thread is continuously wound about the supported and having a thread guide attached thereto formovement about the spaced helical threadsupport members. Such'winding mechanism is especially desirable for use in apparatusfor' formingwide width'net fabricsandat high operational speeds wherein theuse of the rotating thread guide armwinding mechanism has-operational disadvantages caused by inertialand vibration-effects, thread :windage lag, and large vertical space requirements for rotation.

Although the helical supportmembers of suchfabric forming apparatus providemeans for positively advancingxthe weft threads in spaced relation to -form:=the:-weft sheet, there are certainproblems which arise in the-use of the. rotating helicalmembers in conjunction with either the rotating-thread guidearm-type or themoving-belt-type winding means. During rotation of theguide arm or movement of the guide element of the flexible belt and-the'helical members, particularly at high).

operating speeds and/or with helical: members having closely spaced helices, it becomes difficultto accurately coordinate the'rotational speed of the helical members to the movement.

ofthe winding means to ensureythe proper positioning ofa weft thread section between each helix of the helical members; This impropersynchronization frequently causes misplacement of the thread sections such that a thread section resulting in variable lagging of the thread behind the guide arm during the winding operation. With use of the flexiblebelt-type winding means, nonsynchronization most frequently occurs as a result of a stretching or slipping of the belt on the support pulleys driving the belt, causing the position of the thread guide element thereon to be graduallyadvanced or retardedin its cyclic movement about the helical members, such that thread sections eventually are misplaced between the helices of the members.

It is therefore an object of the present invention to provide an improved apparatus of the type described for producing nonwoven textile net fabrics which overcomes the disadvantages of the prior art.

It is a further object of the invention to provide an'improved apparatus for producing nonwoven textile net fabrics having means for controllingthe advancement of the weft sheet by the weft-sheet-forming means of the apparatus in response to a predetermined condition to facilitate uniform positioning of the thread sections in the weft sheet.

The above as well as other objects of the present invention are accomplishedby providing means for controlling the advancement of the weft thread sections on the threadsupport members to form the weft sheet in-response to a sensing of the position of the thread-winding means or the thread itself such that the thread sections may be accurately located in uniformly spaced relation on the thread support members duringtheiradvancement thereby. More specifically, in the use of spaced elongate helical thread support members which are rotated to advance the thread sections in spaced relation along the helices of the members to form the weft sheet, rotation of the members is controlled in response to a sensing of the posi tion of the thread-winding means about the members orthe location of the continuous thread with respect to the members was to facilitate the placement of a continuous weft thread between each .ofthe helices of the-members, thereby prevent= ing misplacement or double placement of the sections in a single helix asa result of nonsynchronization of the winding mechanism and thread support members;

The invention may be further explained and more fully understoodby reference to the accompanying drawings in which FIG. 1 is a schematic side elevation view with parts broken away'of the improved apparatus for forming nonwoven textile net fabrics incorporating features of the present invention;

FIG. 2 is a plan view of the apparatus shown in FIG. 1;

FIG. 3 is an enlarged schematic perspective view of the weft sheet'forming section of the apparatus of F IGS; l and 2 and' showing in more'detail the drive and'control components for operating the winding and weft sheet forming sections of the apparatus;

FIG. 4 is a schematic wiring diagram of the control mechanism of the winding and weft-sheet-forming sections;

FIG. 5 is an enlarged vertical sectional view through the stopcollar of one of the clutch-brake mechanisms of the drive means shown in FIG. 3; and- FIG.- 6 is an enlarged schematic perspective view of one thread support member of the weft-sheet-forming section of a modified form of the apparatus, and showing the location of the sensingmeans'to detect the actual presence'of the continuous thread forming the weft sheet.

Referring more particularly to the drawings, FIGS. 1 and 2 show a schematic-side elevation and a plan view, respectively,

of an apparatus for continuously forming nonwoven net fabrics which apparatus generally includes a thread-winding section 10, a weft-sheet-forming section 12, a warp and'weftsheet-combining section 14, and a takeup roll 16 for collecting the composite nonwoven net fabric.

As shown in FIGS. 1 and 2, thread-winding section includes thread-winding means comprising an endless flexible member or belt which is mounted on a pair of spaced apart pulleys 22, 24 for movement in a generally racetrack-shaped path. Support shafts 25, 26 of pulleys 22, 24 are suitably mounted for rotation in bearings 27, 28 on a support frame 29 and shaft 26 is drivingly connected by suitable sprocket and chain drive arrangement 30 to the drive shaft 31 ofa motor 32.

Mounted on the flexible belt 20 for movement therewith is a thread guide which consists of a double eyelet guide rod 34. As seen in FlGS. 1 and 2, the guide rod 34 has been purposely broken along its length and the ends thereof moved apart to more clearly show the components of the apparatus immediately adjacent the guide rod. During movement of the flexible belt 20 and guide rod 34, a continuous thread 36 is continuously passed from a supply package 38 through a racetrack-shaped guide 39 between the upper and lower reaches of the flexible belt 20, and through the thread guide eyelets on guide rod 34.

The weft-sheet-forming section 12 includes thread support means comprising a pair of elongate spaced thread support members or hollow cylinders 40, 41 which extend in generally parallel side-by-side relation, are of substantially identical construction, and are rotatably supported adjacent their ends in split bearings 42-45 mounted on a support frame 46.

As seen, the surface of each of the cylinders has been helically cut or slotted, and surrounding the cylinders 40, 41 intermediate their length and in fixed relation thereon are split gears 50, 52 which are rotatably driven by intermeshing gears 54, 56, respectively. Support shafts 58, S9 of the respective gears 54, 56 are drivingly connected by a sprocket and chain arrangement 60 and shaft 31, respectively, to the drive motor 32.

As best seen in FlGS. 2 and 3, the outer end of the thread guide rod 34 extends outwardly from the flexible belt 20 to overlap the adjacent ends of the support cylinders 40, 41. During movement of the belt 20, the outer end of guide rod 34 describes a racetrack path about and enclosing the ends of the support cylinders so that the continuous thread 36 passing through the guide eyelet 34a is wound about and laid in a plurality of weft thread reaches or sections R between the cylinders. As the helically slotted cylinders rotate about their longitudinal axes, the thread sections fall into the slots in the cylinder walls and the loop ends thereof are engaged by the helices formed in the walls of the cylinders to be advanced in generally parallel spaced relation along the length of the cylinders to form a weft thread sheet. To permit the passage of the weft thread sections R along the length of the helically slotted cylinders, bearings 42-45 are split with inwardly facing horizontal slots such that the thread sections are free to pass therethrough during rotation of the cylinders. Similarly, the gears 50, 52 mounted on the cylinders are helically split in coextending relation with the underlying slots in the cylinders to permit the unrestricted passage of the weft thread sections along the helical support members. Further details of the construction and operation of the peripherally driven thread support members are set forth in my copending U.S. Pat. application Ser. No. 794,975, filed Jan. 29, 1969, the disclosure of which is incorporated herein by reference.

As seen in FIGS. 1 and 2, the warp and weft-sheet-combining section 14 includes a pair of nip rolls 60, 62 which are rotatably supported by suitable means, not shown, between the outer end portions of the helical cylinders. As the thread sections R being advanced along cylinders 40, 41 approach the outer ends of the cylinders, they pass between and are engaged by the nip rolls 60, 62 where one or more sheets 64, 66 of warp threads supplied from a suitable source, not shown, are combined therewith and pass between the rolls. The combined sheets pass in contiguous coplanar relation by guide rollers through an adhesive bath 68 where a suitable adhesive is applied thereto. The composite sheet thereafter passes over the surface of heated drying rolls 70, 72 where the adhesive is dried and cured to secure the warp and weft sheets together, and the thus formed nonwoven net fabric is accumulated on the collection roll 16. Although not shown, one or more of the rolls in the warp and weft-sheet-combining section, as well as the collection roll 16, may be suitably driven to move the composite sheet through the latter part of the apparatus.

To facilitate support and positioning of the weft sheet during its passage through the apparatus, selvage threads 74, 76 (FIG. 2) are supplied from packages mounted on a cross arm 77 and pass through the centers of the support cylinders 40, 41 to be positioned within the loop ends of the weft thread sections. The selvage threads strengthen the composite nonwoven net product to provide additional support to the weft sheet during its passage through the final sections of the apparatus.

To facilitate uniform positioning of the thread sections of the weft sheet by ensuring that a weft thread section is placed between each helix of the support cylinders 40, 41 during movement of the guide rod thereabout, means are operatively associated with the thread-winding means for sensing a predetermined condition and for advancing the thread sections R along the support cylinders in response thereto. As best shown in FIGS. 2 and 3, this sensing means includes a pair of sensor elements or photoelectric cells 80, 82 respectively positioned at each end of the flexible belt 20 adjacent the pulleys 22, 24. Photoelectric cells 80, 82 are disposed in inwardly facing relation so that the light sources thereof are directed against the outer surface of the belt 20 as it passes around the adjacent support pulleys.

Located on a portion of the outer surface of the belt 20 immediately behind the thread guide rod 34 in the direction of movement of the belt (note arrow in FIG. 3) are light-reflective means, such as a white-painted transverse stripe 20a across the belt. The light-reflective characteristics of the stripe 200 are such that as the stripe passes the light beam of each of the photoelectric cells 80, 82, it reflects back to the photoelectric cells an increased intensity of the light. The selvage thread packages and their supporting cross arm have been omitted from HO. 3 for convenience to better show the operation of the winding and weft-sheet-forming sections of the apparatus.

Each of the photoelectric cells 80, 82 are electrically connected to incremental rotation clutch-brake mechanisms 84, 86, respectively, which control the advancement of the weft thread sections along cylinders 40,41 in response to actuation by the photoelectric cells. Clutch-brake mechanisms 84, 86 may be of identical construction and of the type No. 500339 Model S Clutch-Brake made by Precision Specialties, Inc, of Pitman, New Jersey. Each of the clutch-brake mechanisms operate independently of each other and in response to its respective photoelectric cell to accurately start and stop the rotation of the adjacent thread support cylinder while itself being driven by a continuously rotating source of power from the motor 32.

Clutch-brake member 84 operatively connects the continuously driven drive shaft section 58a to shaft section 58b, and clutch-brake member 86 operatively connects the continuously driven shaft 31 to shaft 59. As is conventional and best shown in FIG. 5 which is an enlarged sectional view of clutchbrake 84, each mechanism includes an input hub 87 and an output shaft 88. The input hubs of the mechanisms 84, 86 are free to turn at all times and are connected to the continuously rotating input drive shafts 31, 58a, respectively, while the output shafts of the mechanisms are suitably connected to the output shafts 58b and 59, respectively. The input hub and output shaft of each clutch-brake are intermittently operatively connected to transmit rotation from the motor 32 to the respective support cylinders by operation of a brake spring 89 which wraps down upon the output shaft upon actuation by the photo cell connected thereto. Specifically, each mechanism 84, 86 includes a rotatable stop collar 91 having one or more radially extending shoulders 92, depending on the selected ratio of the intermcshing gears of the helical support members, which are engaged by a locking pawl 93, the position of which is controlled by a solenoid 94 attached thereto.

In operation, as belt moves to carry the thread guide rod 34 in a racetrack path about the rotatable support cylinders 40, 41, the passage of the painted stripe 20a on the belt is detected by each photoelectric cell which then actuates the solenoid to momentarily displace the locking pawl from the stop collar shoulder. The collar 91 rotates to actuate brake spring 89 and impart rotation to the output shaft and its respective thread support cylinder. Upon one revolution of the collar and support cylinder, the pawl reengages the collar shoulder 92 to disengage the drive shaft of the thread support cylinder from the driven shaft of the motor and cease rotation of the cylinder until the photoelectric cell again senses the presence of the light-reflecting paint on the belt. in this manner, the continuous thread can be positively placed within the helix of each of the support cylinders during passage of the thread guide rod thereabout while the cylinder is stopped, and the cylinder then independently rotated one revolution to advance the thread section and locate the empty helix of the cylinder in proper position for reception of the next thread section. In this manner, rotation of the thread support cylinders is initiated only as the thread guide rod passes the cylinder, thereby compensating for possible advancement or retardation of the thread guide rod due to slippage or inadvertent stretching of the belt during its movement about the pulleys.

The electrical circuit connecting each of the photoelectric cells to the respective clutch-brake mechanisms is best described by reference to the schematic drawing of FIG. 4 which shows the photoelectric cell 80 connected by way of an amplifier 101 to a relay switch 102 which controls the power supply to the solenoid 94 of clutch-brake mechanism 84.

Although the invention has been described in detail with respect to the use of a flexible-belt-type winding means, it is obvious that the improvements of the present invention may be employed with the rotating tubular thread guide-arm-type winding means previously discussed, in which case the sensing means would be positioned to detect the location and/or passage of the guide arm and control the rotation of the spaced thread support members in response thereto. In addi' tion, sensing means other than the photoelectric type may be employed, e.g., mechanical, electrical, etc., and in lieu of sensing the presence of a portion of the belt or rotating tubular guide arm, the sensing means might detect the actual presence of the thread passing onto the support members.

As shown in FIG. 6, a photoelectric cell 110 may be positioned adjacent the end of each thread support cylinder so as to sense the presence of a portion of the continuous thread as it is placed in the initial helix of the cylinder by the winding means. To improve the light-reflecting differential between the thread and the support cylinders, the support cylinders may be painted a dark color, such as black, on thoseportions which receive light from the photoelectric cell. Such a sensing of the actual presence of the continuous thread may be of particular benefit in the use of a rotating tubular thread guide arm type winding means where the continuous thread may lag the movement of the thread outlet of the guide arm due to the windage conditions as previously mentioned.

The foregoing drawings and specification have set forth a preferred embodiment of the invention and, although specific terms have been employed, they are used in a generic and descriptive sense only and not for purposes of limitation.

That which I claim is:

1. Apparatus for producing nonwoven net fabrics comprising thread support means, thread-winding means rnovable about said support means for winding a continuous thread thereabout to form a plurality of thread sections, said thread support means including means for advancing the thread sections in generally parallel spaced relation to form a weft sheet of threads, and means operatively associated with said winding means for sensing a predetermined condition and for advancing the thread sections in response thereto to facilitate uniform positioning of the thread sections in the weft sheet.

2. Apparatus as defined in claim 1 wherein said sensing means comprises means for sensing the position of the continuous thread being wound about said thread support means to advance the thread sections in response to a predetermined position of the thread.

3. Apparatus as defined in claim I wherein said sensing means comprises means for sensing the position of the movable thread-winding means to advance the thread sections in response thereto.

4. Apparatus as defined in claim 1 wherein said thread support means includes at least one elongate helical support member and said advancing means includes means for rotating the member about its longitudinal axis to move the thread sections in spaced relation along the helices of the member to form the weft sheet; and said means for advancing the sections in response to said sensing means comprises means for controlling the rotation of the support member.

5. Apparatus as defined in claim 4 wherein said rotation controlling means includes means for initiating rotation of said support member in response to said sensing means.

6. Apparatus as defined in claim 5 wherein said controlling means further includes means for rotating said support member a single revolution in response to said sensing means.

7. Apparatus as defined in claim 1 wherein said thread support means includes a pair of elongate helical thread support members, means mounting said members in generally parallel, side-by-side spaced relation for rotation about their respective longitudinal axes and for receiving the continuous thread from the thread winding means in a plurality of thread sections therebetween; and said advancement means comprises means for controlling the rotation of said support members in response to said sensing means to facilitate uniform placement of the thread sections between the helices of the members.

8. Apparatus as defined in claim 7 wherein said rotationcontrolling means includes means for initiating rotation of said support members in response to said sensing means for a predetermined amount of revolution thereof.

9. Apparatus as defined in claim 7 wherein said threadwinding means includes an endless flexible member, a thread guide mounted on said flexible member, means mounting said member for movement of said thread guide in a path around said thread support members to wind a continuous thread thereon to form the sections therebetween; and wherein said sensing means includes indicator means on said endless flexible member, and sensor means adjacent the path of movement of said thread guide and flexible member for detecting the passage of said indicator means thereby.

10. Apparatus as defined in claim 9 wherein said indicator means includes light-reflective means on said flexible member and said sensor means includes light-responsive means positioned adjacent the path of travel of said flexible member for actuation by said light-reflective means to initiate rotation of said support member.

11. Apparatus as defined in claim 10 wherein said rotationcontrolling means includes clutch-brake means operatively connecting said means for rotating the support members to said support members.

12. Apparatus as defined in claim 11 wherein said clutchbrake means includes means for initiating rotation of the support members and for stopping rotation of the support members after a predetermined amount of revolution thereof.

13. Apparatus as defined in claim 9 wherein said sensor means includes a sensor element located at each end of said path and adjacent each thread support member to detect the passage of said indicator means thereby; and said rotationcontrolling means includes means operatively connected to each of said sensor elements for independently controlling the rotation of the thread support member adjacent said sensor element.

14. Apparatus as defined in claim 13 wherein said independently controlling means includes means for initiating rotation of said adjacent support member for a predetermined amount of revolution thereof. 

1. Apparatus for producing nonwoven net fabrics comprising thread support means, thread-winding means movable about said support means for winding a continuous thread thereabout to form a plurality of thread sections, said thread support means including means for advancing the thread sections in generally parallel spaced relation to form a weft sheet of threads, and means operatively associated with said winding means for sensing a predetermined condition and for advancing the thread sections in response thereto to facilitate uniform positioning of the thread sections in the weft sheet.
 2. Apparatus as defined in claim 1 wherein said sensing means comprises means for sensing the position of the continuous thread being wound about said thread support means to advance the thread sections in response to a predetermined position of the thread.
 3. Apparatus as defined in claim 1 wherein said sensing means comprises means for sensing the position of the movable thread-winding means to advance the thread sections in response thereto.
 4. Apparatus as defined in claim 1 wherein said thread support means includes at least one elongate helical support member and said advancing means includes means for rotating the member about its longitudinal axis to move the thread sections in spaced relation along the helices of the member to form the weft sheet; and said means for advancing the sections in response to said sensing means comprises means for controlling the rotation of the support member.
 5. Apparatus as defined in claim 4 wherein said rotation controlling means includes means for initiating rotation of said support member in response to said sensing means.
 6. Apparatus as defined in claim 5 wherein said controlling means further includes means for rotating said support member a single revolution in response to said sensing means.
 7. Apparatus as defined in claim 1 wherein said thread support means includes a pair of elongate helical thread support members, means mounting said members in generally parallel, side-by-side spaced relation for rotation about their respective longitudinal axes and for recEiving the continuous thread from the thread winding means in a plurality of thread sections therebetween; and said advancement means comprises means for controlling the rotation of said support members in response to said sensing means to facilitate uniform placement of the thread sections between the helices of the members.
 8. Apparatus as defined in claim 7 wherein said rotation-controlling means includes means for initiating rotation of said support members in response to said sensing means for a predetermined amount of revolution thereof.
 9. Apparatus as defined in claim 7 wherein said thread-winding means includes an endless flexible member, a thread guide mounted on said flexible member, means mounting said member for movement of said thread guide in a path around said thread support members to wind a continuous thread thereon to form the sections therebetween; and wherein said sensing means includes indicator means on said endless flexible member, and sensor means adjacent the path of movement of said thread guide and flexible member for detecting the passage of said indicator means thereby.
 10. Apparatus as defined in claim 9 wherein said indicator means includes light-reflective means on said flexible member and said sensor means includes light-responsive means positioned adjacent the path of travel of said flexible member for actuation by said light-reflective means to initiate rotation of said support member.
 11. Apparatus as defined in claim 10 wherein said rotation-controlling means includes clutch-brake means operatively connecting said means for rotating the support members to said support members.
 12. Apparatus as defined in claim 11 wherein said clutch-brake means includes means for initiating rotation of the support members and for stopping rotation of the support members after a predetermined amount of revolution thereof.
 13. Apparatus as defined in claim 9 wherein said sensor means includes a sensor element located at each end of said path and adjacent each thread support member to detect the passage of said indicator means thereby; and said rotation-controlling means includes means operatively connected to each of said sensor elements for independently controlling the rotation of the thread support member adjacent said sensor element.
 14. Apparatus as defined in claim 13 wherein said independently controlling means includes means for initiating rotation of said adjacent support member for a predetermined amount of revolution thereof. 